Viral infections are very common and cause substantial suffering and hundreds of millions of dollars of economic loss every year. The prevention of viral infections is typically accomplished by administering antiviral vaccines. However, vaccines still cannot effectively prevent an outbreak or epidemic because viruses easily mutate rendering the vaccine ineffective. Some treatments such as interferon or interleukin-2 therapy can inhibit virus replication and improve cell-mediated immune function, but are expensive and are associated with adverse reactions in some instances.
Group V—negative-sense single strand RNA viruses (“Group V”) comprise many human pathogens. These viruses have significantly higher mutation rates compared to DNA viruses generally. The higher mutation rates correlate with faster rates of developing resistance to treatments. Thus, there is a constant need for additional treatments for these viruses.
Group V viruses include many viruses that cause respiratory infections in humans. Respiratory infections, particularly upper respiratory infections (“URIs”) are spread through air and through direct contact by touching of hands to infected surfaces and then touching hands to eyes, nose, or mouth. The nasopharynx, nasal passages, and sinus cavities all play an important role in filtering and housing the majority of these pathogens.
Respiratory Syncytial Virus (RSV) is one pathogen that infects the respiratory tract of humans. RSV is a member of the genus Pneumovirus of the family Paramyxoviridae. Human RSV (HRSV) is the leading cause of severe lower respiratory tract disease in young children and is responsible for considerable morbidity in the elderly and immunocompromised patients. Due to incomplete resistance to RSV in the infected host after a natural infection, RSV may infect multiple times during childhood and adult life. Human metapneumovirus (hMPV) is also a pneumovirus, belonging to the Paramyxoviridae family, which cause a spectrum of diseases similar to RSV, although it is less common than RSV. There is no vaccine or treatment available for either of these infections.
Group V viruses also include viruses in the Bunyaviridae family, which include devastating viral pathogens such as Hantavirus, Crimean-Congo hemorrhagic fever virus, and Rift Valley fever virus (RVFV). As an example, RVFV is a devastating mosquito-borne viral zoonotic disease that causes serious morbidity and mortality in both humans and livestock for which no prophylactic or therapeutic measures are available.
Filoviruses such as Ebola virus are another family of Group V viruses. Each year, Ebola claims many human lives and decimate gorilla populations in Africa. Infection results in an acute fever often associated with profuse internal and external bleeding and death rates of up to 90%.
There is a need for additional methods for the regulation of viral infections and host defenses.